Fluid pressure brake



Sept. 22, 1931.

C. c. FARMER FLUID PRESSURE BRAKE Filed oct. 4, 92's ma. milita: "m

vWNVENTOR CLYDE C.FARMER TTORNEY Patented Sept. 22, 1193.1

.cLYnna FARMER, F QITTSBURG; iENsYLvNI, AssrGNoa 'roman' oF PENNsYLvANlA;

House AIR Bmxneoiviranv, onwiiiyinnmne, rENNsYLvANmA CORPORATION "Appiijcatipii iiiedtbeiffi,lege. ,serial ingu 139,275.

` A brakes.'

In the runningof railway trains, when descending grades, it is desirable to retain a certain degree of luid pressure in the brakeL cylinder when the brake pipe pressure is 1n-Y creased to recharge the auxiliary reservoirs throughout the train. Y

The principal object of my invention is to provide means, under the control ofthe en- Y gineer, whereby the brake cylinder pressure" 15 retaining means may be cutin for grade service and cutout when the train is ruiming on a level.

In the accompanying drawing, the single A ligure is a diagramatic view of a fluid presapplied thereto. v c

As shown in the drawing, the brake equipment may -comprise'a triple valve device 1, connected tothe usualbrake pipe'2, an auxiliary reservoir 3, a retaining valve device 4, connected to the triple valve brake cylinder exhaustppipe 5, and a control valve device 6. y f

The control valve device G'may comprise a casing containing a valve piston' 7, having at one side a chamber '8 connected to the atmosphere through a port 9. Inits lower position, the valve piston engages a seat ring 12, and the chamber 10, at the inner seated area, is in constant vvcommunication with the brake pipe 2,'while chamber 11, at the outer-seated area, is connected through a passage 13 with chamber. 8. Y y

When the valve piston 7 isin the opposite position to that shown in thevdrawing, or so that it seatsy against the gasket-14, chambers 10 and 11 are connected together and the upper end of the passagel is closed by the` movement of thevalve piston 7, so that fluid under pressure from the brake pipe 2 acts on the entire exposed lower surface of they valve piston 7. .n

Contained in chamber 8 and operative by the valve piston 7 is a secondary valve 15,

adapted to control the connection between 11 being connected'to' chamber 8, and thence sure brake equipment, showing my inventionV With 'the' valve piston Z sealedagainst the seat 12;' the lc'or'inection between the p triple valve exhaust'pipe 5 and chamber 8 is opened 'by'nvalve 15,sothat when the triplevalve device 1 isin release position, fluid from the '76 brake cylinder may completelyA exhaust-to at- Yrn'os'phere throughpipe', chamber 8, and'ex'- fhaust-port 9 'without retaining any pressure they" brake Cylinder exhaust pipe'y 5 *and the Y Latmosplie-@by Way of. exhaust, passage 9 vfrom"chamber 8.,v 'A coil spring 16' is. con- ;tained in a chambergformedpin the 'valve pis- 'to'n v7 and actsag'ainst'the valve 15.

A spring-17, contained in'chamber '8, acts on f'thef valve7 to hold f said valve Vseated against the seat 12'so`longas theusual' brake pipe pressure is beingem'ployed In operation, the lsame-brake pipe pressure feo maybe ca'i'riedin Lboth level road service and gradefs'ervice,A such, for example, as 70` W'henoperating on a level road, the force ofthe spring 17 i'sjsuch as tohold the valve "65 piston 7 seated'gainst' thefseatjlQ, so that the fluid at bralre'pipe pressure `exerts its opposi'ng'force chamber` lOfonly, the chamber to atmosphere through exhaust portf9.

in the brake cylinder.l y' f "In" order' to adjustY thef apparatus oper- 80 ation on a grade; the brake pipe pressure f increased' to a degree above thenormalpresksure carried' inthe Ybrake-pipe,` sulicient to ca ifise thepressure in chamber10 to overcome ofthe valve piston I to brake pipepressure. The: valve 'pistc'iiv 7 i"s,r thereupon, quickly Y =`shited to 'itsupper position, seatingon,A the l90 lgasket 14 'l and cutting oli.'` communication from1 chamber Y11, throughV passage i13' to Chamberaf The movement of `valve piston-7 to l"perfposition against gasket '1,4 causes the valve "S5 A15 to seatand -to cut olf communication between the'triple valve exhaust p'ipe 5 andthe Vei'zhaust'port 9 to atmosphere: f

' 'Thusingrade:servicewhenfrecharging the i auxiliary reservoir f3, with the triple valve device lin release position and after a service l aA slow blowrdown of fluid under pressure application of lthe brakes, fluid from the .brake cylinder lows to the triple valve exhaust pipe 5, and can escape to the 'atmosp here, onlythrough the retaining valve de` v1ce4. Y

The retaining valve device 4-may provide -fromjthe brake cylinder to some predeter- 'niine'd degree,"such as 2O pounds, atwhich pressure said retaining ifvalve ydeviceV will i automatically close and prevent a further Adecrease in brake cylinder pressure.

The retention of some, predetermined degrec of pressurein the bral're cylinder kwill Y hold the ,brakes f appliedsuiiiciently to "pro- *,vide'tinie for-,recharging of the auxiliary res- .ervoir 3,1afterVV the brakes Vmay be made.

which another application of To again-@adjust the `brake 'equipment vfor operation in ljevelj road service,jthe brake pipe position in which only a restricted area of said piston is exposed to brake pipe pressure, and a spring opposing brake pipe pressure on said piston, the outer seated area of said.

piston being connected to the atmosphere through a passage controlled by the; movement of the piston. i Y A 2. ,Inl a fluid pressure brake, the combination with aY brake cylinder, brake pipe, and triple Ivalve devicefof -ay pressure' retaining valve device having an always open vconnection to the exhaust port offsaid' triplevalve device, anda valve device operated upon an increase in brake pipe pressure above the pressure normallycarried in the brake pipe `for cutting off communication from the brake cylinder to a direct exhaust port.' .i

In testimony fwhereoflhave hereunto set my hand. Y A 'i pressure is-reduced to a'degreeless than the Y normal full service reduction, as Afor instance,

a reduction off-SQpounds from the normal Y7() pounds. Y, At the lowerV brake pipe pressure,

fthe pressureof spring`l7iis suiiicient to start lthevalve piston 7 movingrtowards .its lower position against the seat l2. The initial downward movement of-valvepiston 7 opens the connection-from -passagel to chamber V8,

Vthereby permitting 'fluid at` brake pipe pres- V-sure in chamberylfl to 'suddenly decrease by pon .Thevvalve l5 @12. Chamber ll is thenI connected to'atmosflowing intochamber 8," wherein itsupple- 4 Y `lments-the force fof spring 17 in quickly push- Y 1 phere through the' passage13v andtheexhaust is again' opened by the down- Y Vward movement of theavalve piston 7, thus `connecting the brakecylinder exhaust from l, y

,pipe 5 to 1- atmosphere, fthrough'the exhaust p 'port' 9` asis Ydesiredvl'or level! road servicefas hereinbefore described.l

`.It Willbenoted that` [controll valve; def i vice is so ad]ustedl'thatywhenthevalve piston j 7 has, once beenshift'ed toits upper position,

i thebrake-'pipe.pressurenmaybereduced to ythe usual equalizin g point in making aservice application of the-brakes without causing 'i movement of the valvepistoni'?v to its lower c seat and on the other hand, the vbrake pipe pressure must be increased -a'ypredetermined 'fore :the valve ritsY lower seat.y

vdegree aboverthe'normal pressure carried bep. Y

piston will beshifted from I s Having now describidmy invention, what Y I claim as new and desire to secure' by Letters l; Ina-fluid pressure brake, theQ-c'omb-inai Ytionwith a brake cylinder and brake pipe,

Vof a, valve device, comprising va valve'forcontrolling communication fromthe brake cylv inder lto an atmosphericexhaust port, a pisfr jtOn foroperatingsaid valve having a 'seated A 

